Farnum f



F. F. DORSEY,

. FIELD MAGNET.

APPLICATION FILED JULY 3!. 1918.

1,3 1 4:, 1 32 Patehted Aug. 26, 1919.

' M D STATES PATENT ouron;

IARNUK F. DORSET, OF ROCHESTER, NEW YORK, ASSIGNOR TO NORTH EAST ELECTRIC COMPANY, OF ROCHESTER, NEW YORK, A. CORPORATION OF YORK-p FIELD-MAGNET.

Specification of Letters Patent. 1 Patented Aug. 26, 1919..

Application filed July 31, 1918. Serial No. 247,611.

To all whom it may concern:

Bt it known that'I, FARNUM F. 'Donsnr,

v aacitizen of the United States, residing at Rochester, N. Y., in'the county of Monroeland. State of New York, have invented certain new and useful Improvements in Field- Magnets; and I do hereby declare the following to be a full, clear, and exact descrip- --tion of the invention, such as will enable others skilled in the art to which it.appe r- .tains to make and'use the same.

This invention relates to a field inagnet.

I for use in electric motors'or generators, or

other apparatus. Y In dynamo-electric machines of the ironclad type,*in which the field-poles are in the form of inward projections from a mg or shell of iron, it is common to use windings, upon the polar projections, comprising form-wound coils which are placed, already wound, on the'piojections. To combine efliciency with economy of material, the polar projections should have comparatively slender necks and-wide faces, but this form in ent' invention.

troduces difliculty in applying the coils to the projections, unless the' projections are made separable, in whole or in part, from the ring ,or shell of the field-magnet.

.The object of the present invention is to produce a magnet, of the type in question, in which'the polar pro ections are connected integrally, without any break in the magobliquely through the polar projections, this.

mode of division facilitatingthe application of the coils, ashereinafter eitplained, without introducing any break or air-gap into the magnetic circuit. I

In the accompanying drawings Figure 1 is a side-elevation, partly in section, of a two-pole field-magnet embodying "the prestohug the parts 6 closely.

I Fig. 2*is a side-elevation showing the'manner in. which: the parts of the magnet are assembled. Fig. 3 is a sideelevation ofa four-pole magnet.

In Figs. 1 and 2 the inventionis shown as embodied in a bi -polar'field-magnet. The

core of the magnetcomprises two'similar' sections which, together, constitute the usual circular yoke, with inwardly directed polar .proj ections. .Each section comprises a bodyportion5, at the ends of which are inward projections 6 and 7, terminating in horns 8 and 9, respectively. The parts 6 and 7 of. the two sectlons meet on parallel planes :10, so. as to form two comparatively nar row necks on which the coils 11 are mounted in the usual manner. v

The planes of cleavage .10, since they pass approximately lengthwise: through the polar projections, do not interrupt the continuity of the paths of the magnetic lines of force,

but they permit the coils, already formed, to be placed upon the necks, in the manner shown in Fig. 2. Itwill be apparent that if the coils be passed over the-horns 9 and seated against the parts 7, asshown, the two core-members may then he slid together, by relative movement .along their meeting faces,- so as to pass the horns 8' through the "coils, and the completion of this movement causes the coils to swing intoposition The two core-member's may be supported in cooperative relation in any convenient way: In Fig. l they are shown as embraced by .a cylindrical shell 'or housing 13, which be important, the outer corners of the sectioris may be roundedofi as. shown by the dotted lines 12 'in Fig. 1, without any sub- .stantialsacrifice of efiiciency. The sections may also be made, either solid or laminated,

as may be most convenient.

- The invention is applicable to multi-polar field-magnets as wellas to bi-polar. Fig.3

shows a four-pole magnet, which differs from that of Fig. 1' only .in that the body portion '14; of each section 'an'arc of on1y 90.

maybe of magnetic or non-magnetic ma- .terial. If economy of material and'weight extends through The invention claimed is: obliquely through opposite polar projec- A field-magnet comprising an annular tions, into a, plurality 'of sections, each secbody and inwardly directed polar projectioncomprising a yoke or body-portion and, 10

'tions,- each projection having a neck and at each end, approximately half of'a, polar 5 horns atthe inner end of the neck;- the projection.

magnet; bein characterized by the fact that t it 1s div'ide on parallel planes passing FARNUM F. DORSEY. 

